Engine and Transmission Tech

OK, help me out on this one guys... Car is running very rich - can tell by the smell & burning eyes. Tried to adjust yesterday using vacuum gauge method where you close the idle circuit screws till the car runs rough, then open slowly till max vacuum. Problem was with both screws fully closed the engine is still running and not very rough. I only lost a few inches (? Not actually sure what the scale is) of vacuum. Tach isn't working so don't know for sure but idle sounded to be in the 1000 rpm range. Given engine runs w/idle screws all the way in, I think that has to mean either idle is high enough I'm off the idle circuit or maybe fuel pressure is too high and its coming in that way. Make sense? I can check the pressure but it was at about 4.5 lbs last I looked so doubt it's that. What controls whether I'm on the carbls idle circuit? If RPM affects it about where does it switch? I checked the throttle linkage. Idle speed screw is out (not touching throtle mech.) and throttle is closing completely. Also, carb is a manual choke and choke is open. Carb is Edelbrock and new so not worn.

Hey Rob,
I'm assuming that you have one of the 1400 series Edelbrocks.
A couple of possibilities are.
The secondary's are stuck slightly open (check the linkage. I have seen a few that get bent during shipping), or the primary's are held open by the fast idle cam.
Remove the carb and visually confirm that they are closed.
A perfect carb will not show any light through the closed throttle blades.
With the throttles completely closed your engine should not run at all
If it does it must be getting air from somewhere else.
A very likely candidate is a carb to manifold miss match.
The idle circuit is controlled entirely by throttle opening. Idle ports and transfer slots are manipulated by the primary throttle blades during the first few degrees of throttle opening.
Checking the fuel level is important on these carbs as they have two floats to deal with. But a quick and easy way to see if you have a problem is to look down the carb throats while it's idling, if you see any fuel dripping from the boosters then you have a problem.
These Edelbrock/Carter/Weber carbs are a good unit and pretty reliable.
Generally running problems stem from an installation glitch rather than the carb itself.
Hope that helps
Cheers
Fred

Quote: Generally running problems stem from an installation glitch rather than the carb itself.

Got it -- so basically you're saying it's my user error ;).

Ok, pride swallowed & thanks for the things to check Fred.

If linkage isnt' bent & butterflys are closing I should be able to where air's getting in by spraying some carb cleaner around the base of the carb -- it should accellerate when I hit the spot I think. What do I do to fix it if that shows it is a mismatch in carb to manifold? (assuming I didn't do something silly like omit the gasket of course -- which I'd like to believe I didn't but since my fan was backwards 1st time out, I'll double check for sure). It's getting enough air to run fairly smoothly so it'd have to be a reasonable leak...

What kind of manifold are you running Rob? And is the carb a 1400 series AFB?
If it's not a square bore manifold then you will need an adapter to fit the edelbrock carb.
Not a big fan of using flammable substances to find vacuum leaks.
A spray bottle with water works just as well and it won't burn the garage down.
When you hit the leak the engine will start to miss and you will hear the water getting drawn in.
Don't be tempted to use a stethoscope to locate the leak like one tech I know.
He found the leak and ruptured his eardrums all in one easy movement!
Some say he sucked out some of his brains as well, but I happen to know that that's a preexisting issue for him.
No need to involve your pride Rob, I'm certain it was the parts guy's fault. :-)
Cheers
Fred